1. FIELD OF THE INVENTION
The present invention relates to aqueous insulating varnishes.
2. DESCRIPTION OF THE PRIOR ART
Hitherto, almost all insulating varnishes and particularly wire enamels are the so-called solvent type varnishes in which an organic solvent such as cresol, xylene or naphtha is used. These varnishes have the defects that the solvent and gases of decomposition are dispersed in the air in the production of the insulated wires and the cost is high because the solvent should be completely incinerated by a combustion furnace. Further, organic solvents not only cause environmental problems such as air pollution but also the working environment is not always good because of the bad odor and fire is always a hazard because the solvents are inflammable. Recently, it is particularly desired to obtain insulating varnishes which do not have those defects that give rise to a poor environment.